Efficacy of quantitative RT-PCR for detection of the nucleoprotein gene from different porcine rubulavirus strains

Blue-eye disease is an emergent viral swine infection caused by porcine rubulavirus (PoRV). We have developed a qRT-PCR method to detect and quantify expression of the nucleoprotein gene for different PoRV strains. The limit of detection for this assay was 10² copies of synthetic RNA. Viral RNA from PoRV was detectable at a TCID₅₀ of 0.01. Significant differences were observed between viral RNA quantification and virus titration results for nine PoRV strains. For nasal and oral swab samples that were collected from experimentally infected pigs, the qRT-PCR assay was more sensitive (87.1–83.9 %) for the detection of positive samples than methods involving isolation of virus. The implementation of highly sensitive assays that yield results quickly will be of great assistance in the eradication of PoRV from Mexico. We also believe that the newly developed qRT-PCR assay will help reduce the spread of this viral infection to other countries.